學生：謝明修 指導教授：王振乾

1. Polylactide, Nanoclay, and Core–Shell Rubber CompositesTongnian Li, Lih-Sheng Turng , Polymer Engineering Center, Department of Mechanical Engineering, University of Wisconsin – Madison,1513 University Avenue, Madison, Wisconsin 53706Shaoqin Gong , Department of Mechanical Engineering, University of Wisconsin – Milwaukee, 3200 North Cramer Street,Milwaukee, Wisconsin 53211Kurt Erlacher, Bruker AXS Inc., 5465 E. Cheryl Parkway, Madison, Wisconsin 53711 學生：謝明修 指導教授：王振乾

2. Abstract ◎ 利用雙螺旋擠壓機熔融混合，製備出polylactide(PLA)/nanoclay、PLA/core-shell rubber 和 PLA/nanoclay/core-shell rubber。 Nanoclay : 有機改質蒙脫土(Cloisite 30B and 20A) Core-shell rubbers : core (polybutylacrylate)，shell (polymethylmethacrylate) Paraloid EXL2314 ：表面處理 epoxy functional group EXL2330：無表面處理 ◎ 探討PLA與 nanoclay 和 rubber 結合之機械與熱學特性。 實驗結果發現，PLA 分別添加兩種 5 wt% nanoclay，增加其模量及相當的 impact strength，降低 tensile strength 和 strain at break。（PLA/nanoclay） 另ㄧ方面，PLA/EXL2330 的複合物，rubber 添加至10 wt% 或者更多可得到較大的 impact strength 和 strain at break ，但是模數和強度皆低於純PLA。（PLA/core-shell rubber） PLA同時添加5 wt% nanoclay ( Cloisite 30B ) 和 20 wt% EXL2330，增加134% impact strength、6% strain at break，模量相似，降低28% tensile strength。（PLA/nanoclay/core-shell rubber）

3. Introduction Core-shell rubber particles 的添加可使 thermoplastic 或 thermoset 材料變得堅韌。組成 core 的部份為已交聯的彈性體，而 shell 部分為 thermoplastic，在高分子混摻中 thermoplastic 可使 rubber particles 具有較佳的分散性 。 一般 core-shell rubber particles 的粒徑尺寸約在 50-500 nm。 影響韌性修飾的因素包括：（1）rubber 的玻璃轉移溫度，（2）rubber 在高分子混摻的粒徑大小，（3）分散性，（4）對高分子基材的附著性。

5. 30B Θ=4.75° D=1.86nm 20A Θ=3.30° D=2.67nm FIG. 2. TEM image for (a) PLA-30B-05 and (b) PLA-20A-05. FIG. 1. Wide-angle XRD patterns for (a) PLA, Cloisite30B, and PLA-5 wt% Cloisite30B nanocomposites, and (b) PLA, Cloisite20A, and PLA-5 wt% Cloisite20A nanocomposites.

6. FIG. 3. Weight loss versus temperature measured by TGA for Cloisite30B and Cloisite 20A.

7. FIG. 4. The melt flow indices (MFI) of PLA (extruded and molded samples) and PLA–MMT (Cloisite30B or Cloisite 20A) nanocomposites (extruded samples) at various loading levels after melt compounding.

9. FIG. 5. The effects of adding core–shell rubber on the (a) impact strength, (b) strain at break, (c) tensile strength, and (d) tensile modulus of PLA core–shell rubber composites.

10. FIG. 6. Wide-angle XRD patterns for Cloisite30B, PLA, and PLA-30B- 05-EXL2330–10 nanocomposites.

11. FIG. 7. Enlarged view of the peak regions for PLA-30B-05 and PLA- 30B-05-EXL2330–10 composites. The curves plotted the azimuthally Averaged intensity of the three composites listed on the plot with the azimuthally averaged intensity of pure PLA subtracted. [Color figure can be viewed in the online issue, which is available at www.interscience. wiley.com.]

12. FIG. 8. TGA thermograms of PLA, EXL2330, PLA-30B-05, and PLA- 30B-05-EXL2330–10 composites.

14. Conclusions • 添加nanoclay、core-shell rubber 可有效改善PAL的機械性質。 • 研究中發現Cloisite 30B 相較於20A 親水，故適用於親水性的PLA，且插層的程度也比較好。 • Core-shell rubber 的研究，EXL-2330 可有效的增加PLA之堅韌性，添加至 PLA-30B 也可促進插層的程度。